Insulator



June 10, 1930. MILLER 1,763,170

INSULATOR Filed Feb 19, 1927 IN VENTO R F an cH/W/er.

A TToRNEY A VHTNESSES I Patented June 10, 1930 UNITED STATES PATENTOFFICE FBEDEBIC H. MILLER, 01' WILKINSBURG, PENNSYLVANIA, ASSIGNOR T0WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OFPENNSYL- VANIA INSULATOR Application filed February 19, 1927. Serial No.169,487.

My invention relates to insulators and particularly to insulators thatare adapted for extremely high-voltage service.

One object of my invention is to provide 5 an insulator, of theabove-indicated character, that shall improve the mechanicalcharacteristics of an insulator of a type heretofore suggested.

Another object of my invention is to pro- 10 vide an insulating elementthat shall substantiall simulate a solid insulating rod but that shallbe so vertebrated or sectionalized and held together as to eifect amaterial improvement in the service for which it is intended.

A further object of my invention is to provide a high-voltage insulatorthat shall be simple and durable in construction, economical tomanufacture and effective in its operation.

Heretofore, it has been usual, in insulator practice, to provide pillarstructures composed of a plurality of superposed insulator units havinexposed metal terminals, laterally extendmg petticoats and otherfeatures inimical to my invention, as well as to provide outer tubularshells, both unitary and sectionalized, having means, extendingcontinuously therethrough, from terminal to terminal, for the mainmechanical support.

It is my aim to provide a structure that, in contra-distinction to theabove-mentioned pillars, has the appearance and effect of a solidinsulating rod having a continuous outer surface and, incontradistinction to those structures embodying tubular shells havingreinforcing members extending therethrough, is composed of sections,each constituting a component part of the main insulating resistance andin which metal or other connecting means is completely enclosed.

In co-pending application, Serial No. 548,- 818, filed April 1, 1922, byH. B. Smith and assigned to the Westinghouse Electric and ManufacturingCompany, to which reference may be had for a better understanding ofthis invention, is set forth an insulator which utilizes, tosubstantially maximum advantage, the insulating characteristics of along straight rod. It operates on the principle of keeping electrostaticstresses of any consid- A one-piece rod of refractory material,

such as porcelain or glass, may be more or less difficult to manufactureabove a certain size and, by reason of its hard or brittle nature, maybe subject to greater bending fracture than a rod of wood or other moreyieldable material. However, such refractory material has inherentelectrical advantages over other materials, especially in outdoorhigh-voltage service, and it is one of the purposes of this invention toretain these advantages, and, at the same time, to provide otherfeatures that are not present in a single-piece refractory rod.

Accordingly, in practicing my invention, I provide a refractoryinsulating structure that, in appearance and operation, is similar to asingle-piece rod but is so composed of transversely-divided componentsections and so held together as to have great mechanical strength and adegree of lateral flexibility not found in single-piece refractory rods.

Figure 1 of the accompanying drawing is a longitudinal side view,partially in elevation and partially in section of an insulatorembodying my invention; and

Fig. 2 is a sectional view taken line II II of Fig. 1.

The device comprises, in general, upper and lower terminal structures 2and 3, respectively, that are joined by the insulating rod structure 4of my invention.

As set forth in the above-mentioned copending application, the terminalmembers 2 and 3 are so constructed and related to each other and to therod 4 as to prevent concentration of the electrostatic field at anypoint, to widely distribute the field at all points, and to cause it tohave a materially weakened central portion through which the rod 4extends.

along the These features are obtained by having widely rounded portions5 and 5 on the members 2 and 3, respectively, that are laterally spacedfrom the rod and disposed inwardly therealong from the end portions ofthe nieniber 4, thus causing the field to extend between the terminalmembers in the form of a tube having a greatly weakened central portion.

The rod 4: comprises a plurality of axiallya-lined end-to-end orseriesrelated insulating blocksti that are preferably of uniformcylindrical form of substantially the same diame ter and constructed ofrefractory insulating material, such as porcelain or glass.

Metal plates or end members 7, of substantially discoidal form, aresecured to the blocks 6 for attaching the latter to eachother. Theseplates have openings symmetrically distributed about the centers thereoffor the reception of stud or bolts 8 which are secured in small openingsin the blocks 6, as by bodies 9 of cement, metal alloy, or othermaterial. The plates 7 also have longitudinallyextending aperturedcentral portions 10 of substantially cup-shape, for the reception ofbolts 11 which hold the block units together.

Flanges 12, constituting continuations of the cylindrical sides of theblocks 6, project downwardly from the lower end of each to enclose allof the metal parts 7, 8 and 9. These flanges extend to within arelatively short distance of the next lower blocks, so that, inappearance, the structure resembles a smooth one-piece rod.

The terminal member 2 is secured to the top block 6 by bolts 1a whichare secured to the block similarly to the bolts 9.

Similarly, the lower terminal member 3 is secured to the bottom block 6,as by bolts 15.

The above structure, since there are no metal or other elementsextending continuously through the block 6, from the terminal 2 to theterminal 3, places the blocks in tension and utilizes the fullinsulating value thereof and, since the metal interconnecting parts 7, 8and 9 are completely submerged by the insulating material, theelectrical characteristics of the device, as a whole, are not materiallychanged from what they would be if the structure were entirely ofinsulating material.

Further, there is a slight inherent lateral flexibility that would notbe present in a rod of solid refractory material extending from theterminal 2 to the terminal 3.

\Vhile I have shown and described a particular form of my invention,changes may be effected therein without departing from the spirit andscope thereof, as set forth in the appended claims.

I claim as my invention 1. An insulator in the form of an elongatedcylindrical rod of inorganic dielectric material having smooth sidesurfaces of uniform diameter and constructed of closely end-toendrelated longitudinal sections, one of said sections comprising a mainbody portion and an annular end flange projecting therefrom to aposition closely adjacent to a next adjacent section to provide a spacebetween said oneand said adjacent section, and detachablesectioirconiiecting means having portions in said space.

2. An insulator in the form of an elongated cylindrical rod of inorganicdielectric material having smooth side surfaces of uniform diameter andconstructed of closely end-toend related longitudinal sections, one ofsaid sections comprising a main body portion and an annular end flangeprojecting therefrom to a position closely adjacent to a next adjacentsection to provide a space between said one and said adjacent section,and detachable centrally-cooperating section connecting means havingportions in said space.

In testimony whereof, I have hereunto subscribed my name this 11th dayof Feb, 1927.

FREDERIC H. MILLER.

